


all you have is your fire

by tossedwaves



Category: Harry Potter - J. K. Rowling
Genre: Gen, Inspired by The Rigel Black Chronicles, Potions, Ruse Reveal
Language: English
Status: Completed
Published: 2020-11-14
Updated: 2020-11-14
Packaged: 2021-03-08 18:35:16
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,291
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27431353
Author URL: https://archiveofourown.org/users/tossedwaves/pseuds/tossedwaves
Summary: Severus has known for a while that he would do almost anything for Rigel Black. But what would he do for Harriet Potter?
Relationships: Harry Potter & Severus Snape
Comments: 20
Kudos: 133
Collections: Rigel Black Exchange Round 2





	all you have is your fire

**Author's Note:**

  * For [rachel614](https://archiveofourown.org/users/rachel614/gifts).



Severus set the cauldron with its lid down onto the counter of Lab 3 exactly when the knock sounded on the door. “Enter,” he said. 

Rigel was right on time, as usual. 

“Hello, Professor. What are we brewing today?” the boy asked, peering around him to look at the ingredients Severus had laid out. 

He motioned Rigel over to the cauldron. “What can you guess?” he asked. 

“That’s—are we doing area-effect potions today?” Rigel turned to face him. 

“You could benefit from a greater familiarity with them. It’s not my specialty, but I can prevent you from blundering along blindly into whatever ridiculous scenario you find yourself in next.“ Snape carefully omitted all mention of the Tournament. 

Rigel’s sidelong look said that he had noticed, but decided not to comment for the sake of the potions lesson. Snape approved. The boy had to learn, one way or another. 

He pointed at the cauldron. “Now, what can you tell me about the potion?”

“Hm, there’s peppermint for clear-sightedness and mullein for disruption.” Rigel frowned in thought. “Maybe something to do with breaking illusions?”

“You are correct. Have you heard of Thief’s Downfall?”

Rigel pursed his lips. “It’s the potion they use in Gringotts on the ride to the deeper vaults. It’s supposed to break every illusion and potion, including Polyjuice, with a touch. However, since it’s in liquid form, the object with the illusion needs to be completely drenched with it to transform back. That’s why the Gringotts cart goes right under a waterfall.” He glanced up at Snape. “But if we’re making Thief’s Downfall, why does the cauldron have a lid?”

Snape nodded. “That is because we are not making Thief’s Downfall. We are making a similar potion that is an area-effect potion. This one is meant to combat potion-based and rune-anchored illusions, since those are often larger objects that it would be infeasible to spray a liquid all over. It’s mainly used in curse-breaking. Goblins don’t use this because it’s more expensive than the liquid form.”

“Also, I doubt they care about drenching their visitors.” Rigel smirked.

“And that too,” Snape’s lips twisted upwards. “But I thought it would make good practice for area-effect potions. You need to learn how to brew and identify them better. This one will be a challenge because you will need to keep the lid on throughout the entire brewing process. This is the tube you will use when adding ingredients.” He pointed at the tube attached to the cauldron which was similar to the one used for layered potions. “It will prevent the gases from escaping.”

Rigel’s smile looked even wider than usual. No doubt the boy was excited at the thought of a new challenge. Merlin knew how hard it was for Severus to come up with new potions challenges for him. Rigel had even taken to freebrewing with a talent that was unprecedented, not that Severus would ever tell him that. It did not do to get a swelled head. Severus himself had learned that lesson the hard way. 

The brewing started off well. Rigel handled the ingredients as deftly as usual, and Snape sat back and watched. The next stage would prove tricky, since the peppermint had to be aerosolized and added last, once the potion was fully in a gaseous state. 

Before Rigel began that process, he looked up to Snape for direction, but Snape only nodded. He had instructed Rigel in the theoreticals of the technique in a previous lesson, and now it was up to Rigel to do it on his own. Freebrewing was all about getting a personal feel for the interactions between ingredients, and if Rigel wanted to use area-effect potions, he would have to learn how to handle gaseous potions sooner or later. Though Rigel had avoided any serious mishaps so far, thanks to his extraordinary magic, it was only a matter of time before one happened. This was why Snape had chosen some of the least reactive or dangerous potions to practice on first. Rigel was due a mistake soon—overconfidence would only lead to disaster—and it would be far better for him in the long run to experience that in a controlled environment. 

As if Snape’s wandering thoughts had brought it about, he soon noticed that Rigel had pumped the peppermint in at slightly too high a pressure. It would result in a too fast reaction, and Snape knew that in a few seconds, the whole potion would blow over. He readied the laboratory shields to block off the fumes. 

However, once again, Rigel’s magic was too fast for him. It flooded the potion as it had done after all of Rigel’s previous mishaps, only this time, instead of shutting the reaction down, the magic only made the problem worse. The gas absorbed the energy from Rigel’s magic and exploded outwards, enveloping the whole room before Severus could finish raising the shields. 

Snape bit off an oath. It was certainly annoying, and he wouldn’t enjoy sterilizing the whole room and throwing out all the ruined ingredients, but at least the potion, despite its extra energy boost, didn’t seem to be dangerous. He would need to talk to Rigel about his involuntary magical response, though. He had been meaning to ask what it was, and this explosion only showed that magic couldn’t be played around with. They were lucky that there hadn’t been any worse effects. 

A gasp tore Snape’s attention away from his wandering thoughts. A quick glance showed Rigel beside him, only...something was off. His eyes narrowed. 

Snape remembered that day on the Quidditch field, where Rigel’s face had contorted in what had looked like the effects of Polyjuice wearing off. Snape had later dismissed such suspicions as ridiculous after monitoring him for Polyjuice the entire week after, but—it was unmistakable now. 

Rigel abruptly spun on his heel and dashed for the door, but Snape was prepared this time. A wave of his wand had the door locked and secured, and even the press of Rigel’s magic could do nothing to reopen it. Snape summoned the boy’s wand for good measure. He would get answers, this time. 

“Please, sir, I’m going to be sick,” Rigel pleaded, though his voice was higher than usual. He clawed at the door as his body bubbled and contorted and grew shorter. From the back, Snape could see Rigel’s hair get messier and his shoulders narrower. 

He could only stand there in shock. Snape had suspected Polyjuice, and he was a naturally suspicious person, but he had never expected something like this. It almost looked as if Rigel were an entirely different person. 

“Who are you?” He strode forward and grabbed the boy by the shoulder to spin him around. “Who are you, and what have you done to Rigel Black?”

He felt a wave of magic rise up around the boy, but without a wand to direct it further, Snape could easily dissipate it. He tugged the boy around and met a pair of shockingly green eyes. 

Green eyes! He had never seen eyes of such a colour; even Lily had not had eyes so shockingly bright. He took a step back. The eyes were framed by a shock of messy hair only rivaled by Potter’s mop. The face was tanned like Rigel’s had been and some features bore a passing similarity, but there was no doubt that Snape was looking into the face of an entirely different person. 

“Sir, it’s not what you think—! I can explain! I just wanted to see what it would be like learning under you for a day. Rigel and I were going to switch back again tonight. It was just a temporary—“

“Spare me your lies! I am not a dunderhead, don’t expect to fool me with such a ridiculous story. Who are you, and what could have possessed Rigel to switch places with you for a day?”

The boy’s face blanked in the same way Rigel’s always had when he was at his most evasive. “I just wanted to see what Hogwarts was like; I didn’t want to cause any trouble! I’m sorry, Professor.”

Snape’s eyes narrowed. “And you thought you could just pass yourself off as Rigel? But no—this makes no sense. Your occlumency shields, they are the same.” He took a step back in shock.

The boy’s eyes widened in panic, but Snape was not done.

“I had thought, after the incident last year, that Polyjuice might be involved. But my examinations revealed nothing and I had thought that perhaps it was simply a trick of the light. But this—you have been pretending to be Rigel all along. Your mannerisms, your brewing technique, they are all the same.” He took a threatening step forward and raised his wand. “You will tell me who you really are, or you will wish that you had never met me.”

The boy raised his face in supplication. “Sir, I beg of you. Please, for both our sakes, don’t ask this of me.”

He examined the boy’s features again. But no—could it be—he had noticed the similarity earlier. Lily’s eyes and Potter’s hair. And Rigel and Harriet Potter had always had that strange relationship—

“You are Harriet Potter.” His voice was flat. There was no other explanation. 

The boy—girl—pinned herself back against the wall and shook her head, but it was futile. There was no turning back for either of them now. 

She kept denying the inevitable. “There’s a Sealing Curse. If you allow me to seal you, there’s no way you can get in trouble. I’d do almost anything—please, sir, don’t turn me in. I’d be thrown in Azkaban and my family—“ 

Snape snarled. “Be silent! Let me think.” He spun on his heel and brandished his wand at the door, forming a complex series of incantations that warded the door against intruders and eavesdropping of any kind. It had a nasty hex waiting for anyone who would force the issue, one of his personal inventions. Snape then turned on her. 

Her face was paler than Snape had ever seen it. It seemed like she had realized the predicament she was in. She knew further protests would do nothing to sway him, not right now.

But Rigel—

“Give me time to think about this.” Her mouth opened as if to protest again, but she saw his face and blanched. He pointed his wand at her. “If you attempt to break out of my wards and flee, I will send the hounds of hell after you.”

He waited until he saw her nod, then turned on his heel and fled the room. The lab was hardly an ideal place to leave him—her—whoever they were, but at least it was secure. And he needed to think. He keyed in his magical signature to secure the door, then stumbled out the door and across the hall to his office. Barely breathing, he walked over to his desk and collapsed onto the chair. 

Severus reached into the drawer of his desk to grab the package of ginseng with one hand and the medi-mini with the other. He sat there with the two in either hand for what must have been minutes.

His apprentice Rigel Black was actually Harriet Potter.

Speaking of, does James Potter even know? He remembered noting that Rigel had interacted strangely around Sirius. Whether that meant that no one knew or only Sirius didn’t, Snape could not say. But if that meant—could it be—that James Potter had been in on this all along? That he and his happy wife and happy family had been laughing behind their backs the whole time, _Silly Snivellus thinking that he had been important to someone, that someone understood for once, someone finally worthy of all he had to give,_ had just—had just been in his head the whole time.

The packet of ginseng flopped open and it spilled out all over the floor, shredded heaps of pale yellow all over his potions boots and floor, too dirtied now to ever use in a potion.

He remembered Lily, her face lit up with a smile she used to show just for him, the way she’d laugh, “Sev, Sev, no one could possibly care about potions as much as you!” That smile twisting into a blank face, cold as the winter winds, a regretful smile across a hospital room...

He grabbed at the pile of ginseng, but the powder slipped through his fingers, leaving even more of a mess. Snape let out a curse and grabbed his wand with shaking fingers to Vanish the whole blasted lot of it. He’d been a fool. 

He had known that there was something off about Rigel since first year. No child could possibly be that contained without something to hide. Even though it seemed as though Rigel had confided more in him with each year, the deception had likely grown deeper and deeper. Rigel answered personal questions with lies layered on top of lies, and Severus had long grown resigned to never understanding his convoluted life story and relationship to his cousin.

Snape slashed his wand around and threw a curse at the medi-mini, still the same bright green it was three years ago. Only, instead of exploding like it should have, it just absorbed the curse and sat there innocuously on his desk, taunting him with the remembrance of Rigel. Snape stared at it.

But no, he was wrong. It couldn’t have been entirely a ruse. 

There was too much heart in Rigel—in Harry—for all of it to have been fake. Snape had been on his guard with Sirius Black’s son at the beginning. No less than an absolute devotion to potions could have gotten him to take Rigel as an apprentice. Even if the whole ruse had been a cruel way to get back at greasy Snivellus, there had been moments of honesty. He remembered the hours they had brewed together, the strange excitement in Rigel’s eyes at the most mundane aspects of potioneering—the same excitement that Snape had, even though no one else could or would understand.

Snape had thought he’d finally found a purpose, something he could finally do and be proud of. His entire life had sometimes seemed a loss, a perpetual atonement for past mistakes, but then in walked a boy with so much talent and ambition and goodness that it seemed as if Snape’s future began to lay itself out before his eyes. He had sworn to do anything to help the boy, and if that meant accepting his old rival Sirius Black too, then he had done more painful things to protect the people he l—cared for. Snape would have done a lot worse for Rigel. 

Now, it looked increasingly likely that unless he put his life and magic on the line for Harriet Potter, Rigel would exist no more. Perhaps Rigel was already gone, only a temporary face for Harry to use. But even though it had been a ruse, Severus knew that there must have been some truth to it. Rigel Black had never existed, but Harriet Potter always had. 

Perhaps some would argue that blood identity theft immediately invalidated any rapport that the two of them had developed, that such a despicable crime made any relationship a tower built on sand and propped up by lies. But if Snape criticized this ambitious halfblood who had done anything to pursue her dream, he would be nothing more than a hypocrite. How many times had he wished for another way as a child, had begged and pleaded and blurred the lines between what was right and good and pure self-interest until he no longer recognized the person standing in front of him? Severus, the boy at Spinner’s End, the Half-Blood Prince, Lily’s ex-best friend, prominent figure of the SOW party? He had wanted to demolish his old self, and to this day he could not tell if he had succeeded. Some days Snape could barely stand to look at himself in the mirror. What right had he to judge Harry for making the same mistakes he had, with infinitely better results?

But what could he do? The Unbreakable Vow he had sworn years ago hung over his head like the Sword of Damocles, always haunting his steps. But—Snape had some leeway. He hadn’t thought about it much, resigned to the inevitable, but his vow to the SOW Party could be circumvented. He had only sworn to support Riddle. It didn’t refer to anyone else, and besides, revealing Harriet-as-Rigel would only hurt the Pureblood Tournament. And that would be devastating to Riddle’s reputation. No, he couldn’t reveal the ruse. 

If he backed her, though—it could jeopardize everything. He would not regret his loss of worth in Riddle’s eyes, but Lord Riddle had a serpent’s tongue and a scorpion’s tail. If Riddle ever caught his duplicity, he would not live long enough to regret. 

Even if Dumbledore managed to protect him, his years in the SOW Party had not been entirely a loss. His friendship with Lucius was built upon half-truths and a delicate balance of power, but it was a friendship nonetheless. And his relationship with Draco was one of the good things that still remained in Severus’ life. He could not make himself pretend that that would remain, should he betray in such a way. 

And Draco—how would he react to Rigel’s deception? He could not begin to predict how that would go or how much it would hurt him, but he knew that it would not end well. Snape knew what it was like to lose friends. He would never have wished that on either of them. 

No, Harry’s deception must never be revealed, but how could that ever be ensured? British society was built upon a slippery web of secrets and lies, but truth had the inconvenient habit of revealing itself now and again. And if it ever did come to light—well, Severus was hardly the most dangerous person who would have opinions about it. 

He saw Lily’s face in his mind’s eye and knew that this was what she’d want for him to do. But that was in the past; he’d fulfilled his debt to her, as much as was possible, anyway. Lily was no longer his primary motivator. 

Severus had never been a selfless man. Stupid Gryffindor bravery to achieve unending accolades was never his way. Snape was Slytherin to the bone—he cared about his people. Once that had meant Lily. 

But his primary loyalty was to Harry now. With whatever breath he had left in him, he would ensure that she could go as far as she wanted. If that would eventually mean the end of him, well—Snape had sworn his life to far less worthy causes.

* * *

When he got back to Lab 3, Harry was standing on the other side of the room. She hesitated, looking up at his face, but with a deep breath, she walked over to him. 

“Sir, have you decided what you’re going to do?“ Her stoic face couldn’t hide the apprehension in her eyes. 

“I don’t know what you mean, Potter,” he pointed at the shrivelfig, “but you have ingredients you need to prepare. You can’t learn freebrewing through osmosis, no matter what the dunderheads in my classes believe. Never let it be said that Severus Snape didn’t teach his apprentice all he knew.”

And though Severus knew he had a heart as scarred and black as coal, well, if it warmed a bit at Harry Potter’s beaming smile, no one had to know.


End file.
